Many specific aspects of capacitor design have been a focus for improving the performance characteristics of capacitors used in electronic circuits in extreme environments such as automobile applications including, for example, antilock braking systems, engine systems, airbags, cabin entertainment systems, etc. Solid electrolytic capacitors (e.g., tantalum capacitors) have been a major contributor to the miniaturization of electronic circuits and have made possible the application of such circuits in extreme environments. Conventional solid electrolytic capacitors may be formed by pressing a metal powder (e.g., tantalum) around a metal lead wire, sintering the pressed part, anodizing the sintered anode, and thereafter applying a solid electrolyte to form a capacitor element. In automotive applications, a capacitor assembly may need to have a high capacitance (e.g., about 100 microFarads to about 500 microFarads), operate at high voltages (e.g., about 50 volts to about 150 volts), and sustain exposure to high temperatures (e.g., about 100° C. to about 150° C.) and high ripple currents (e.g., about 10 Amps to about 100 Amps) without failing. Because exposure of the capacitor assembly to a high ripple current can lead to high temperatures within the capacitor assembly, the capacitor assembly can be damaged and its reliability reduced if it is not able to adequately dissipate heat. This problem is compounded when multiple capacitor elements are utilized in order to form a capacitor assembly with a high enough capacitance. As such, attempts have been made to lower the equivalent series resistance (ESR) of capacitor assemblies that include multiple capacitor elements, as a reduced ESR corresponds with the ability of the capacitor assembly to dissipate heat that is produced when the capacitor assembly is exposed to high ripple currents.
Nevertheless, a need currently exists for a capacitor assembly having improved ESR and heat dissipation capabilities when exposed to high ripple current environments and that can also operate reliably at high temperatures and voltages, particularly when the capacitor assembly includes multiple capacitor elements.